I suppose it's useful in designating writing that tends to come from personal experience, work that delineates an "I," but it's a loose lasso, one which may rope certain poems by one poet and not others.
Alec watched them through the half-open door, Jace leaned against the sink as his adoptive sister sponged his wrists and wrapped them in a white gauze. “Okay, now take off your shirt. ” (Isabelle) “I knew there was something in this for you. ” (Jace) ~pg. 329~